Hypodermic syringe



Patented June 5, 1951 UNITED STATES PATENT OFFICE HYPODERMIC SYRINGE Anthony Drabicki, Brooklyn, N. Y.

Application June 6, 1949, Serial No. 97,386

(Cl. 12S-218) 3 Claims.

This invention relates to hypodermic syringes. More particularly, it concerns syringes which are used in conjunction Iwith .ampules having movable piston plugs at one end thereof.

An object of this invention is to provide in a hypodermic syringe, improved means for positively engaging the conventional piston plug of an ampule mounted within the syringe, for the purpose of imparting retracted, as well as advanced movement to the plug, as desired.

Another object of this invention is to provide in `a hypodermic syringe, improved plunger means which may be rendered operative to abut at one end thereof, the conventional, imperforate piston plug of an ampule mounted in the syringe, for expelling the contents of the ampule from the syringe, said plunger being readily convertible to a form wherein said piston plug may be positively engaged to provide retracted, as well as advanced movement of the plug.

While hypodermic syringes have been heretofore provided with plungers which positively engage the piston plug of an ampule to permit retracted movement of the plug, such plungers are threaded and the piston plugs must be formed with suitable means to receive the threaded portion of the. plunger. Accordingly, a further object of this invention is to provide a plunger in a hypodermic syringe which includes a penetrating portion adapted to positively engage a conventional piston plug, upon simple manipulation of the plunger, said plunger being further adapted to be manipulated so as to retract the penetrating portion thereof to an inoperative position, whereby said plunger may be used for i providing advanced movement only of the piston plug, by abutment with the surface of the piston plug.

Still a further object of this invention is to provide a plunger for a hypodermic syringe which comprises a sleeve Ahaving a member slidably mounted therein, said member being Aprovided with a combined penetrating and gripping portion at one end thereof, together with means for selectively moving said member to positions exposing and concealing the penetrating portion thereof.

Yet a further object of this invention is to provide in a hypodermic syringe, plunger means having a minimum number of parts, which is economical to manufacture, which may be readily manipulated to provide alternative forms of piston plug movement and which is practical and efcient to a high degree in use.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements, and arrangement of parts, which will be exemplied in the construction hereinafter described, and of which the scope of invention will be indicated in the claims which follow.

In the accompanying drawing, in which is shown an illustrative embodiment of this invention:

Fig. 1 is a front vertical View of a hypodermic syringe embodying the invention, with parts in section;

Fig. 2 is a front vertical view of the plunger portion thereof, lwith parts in section and showing the same in engaging relation with a piston plug;

Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. l and Fig. 4 is a transverse sectional view taken on the line 4--4 of Fig. 2'.

Referring in detail to the drawing, Il) designates a hypodermic syringe embodying the invention. The same comprises a cylindrical barrel II in which is slidably and rotatably mounted a plunger I2. The barrel includes at its lower end a bored tip portion I3 which is externally threaded. A conventional needle assembly I4 is screwed onto the barrel tip I3. At the upper open end of the barrel II there are mounted laterally extending finger pieces `I5 which may be retained in place by means of a bushing I6 which is screwed into the threaded upper portion of the barrel Il.

The barrel I I is adapted to hold a conventional ampule I1 of anesthetic, medicament or the like. The barrel Il may be cut away as at I8, to allow a view of the contents of the ampule I'I which is made of glass. The ampule Il includes a plug I9 of synthetic rubber or the like, at its lower end. The lower end of the ampule is provided with an opening which admits the needle of the needle assembly I4 for piercing the plug I9, in a manner well known in the art. A movable piston plug 20 of synthetic rubber or the like, is mounted at the upper end of the ampule. The piston plug is of the imperforate type, well known in the art.

The plunger I2 is adapted to provide for forward movement only of the piston plug 20 or alternatively, to engage the piston plug 20 so as to move the same either forwardly or rearwardly. To this end, the plunger I2 comprises a sleeve 2| open at its lower end and formed at its upper end with a threaded shank 22 upon which is screwed a thumb engaging member 23. At its lower, open end, the sleeve 2l includes a portion 24 of enlarged diameter which forms abutment means for the piston plug 2U.

A rod 25 is slidably and rotatably mounted within the sleeve 2 I. The rod has a sliding frictional t relative to the interior surface of the sleeve. The rod 25 terminates at its lower end in a conical shank portion formed with a helical, self cutting thread 26. The rod 25 is formed with a transverse opening 2I at the upper end thereof. A pin 28 is force fitted in the opening 2'I, with one end projecting therefrom.

The wall of sleeve 2l is formed with a longitudinally disposed slot 29, adjacent the upper end thereof. The length of slot 29 is substantially equal to the length of the threaded shank 26. The slot 29 includes a short, right angle offset portion 30 at the lower end thereof. The slot 29 accommodates the projecting portion of pin 28 and limits the longitudinal movement thereof. `The portion 30 of slot 29 limits the rotational movement of the pin 28 when thev same is disposed at the lower end of the slot.

The wall edges dening the slot 29 and portion 36 are tapered as at 3|. It will be apparent from a consideration of Fig. l, that the slot 29 is so disposed that when pin 28 is moved to the upper end of the slot, the rod 25 will be retracted and the threaded shank portion 26 thereof will be concealed within the lower end of the sleeve 2|. The tapered slot edges permit ready manipulation of the pin 28 by means of a finger nail. It will also be noted that the upper end of the pin 28 is substantially flush with the outer surface of the sleeve 2l, thus permitting easy sliding movement of the plunger I2 through the bushing I6.

Upon pressing the thumb engaging piece 23 of the plunger I2, the enlarged portion 24 on sleeve 2| will be caused to abut the piston plug 2U and continued pressure on the thumb piece will result in the expulsion of the contents of ampule I'I through needle I 4.

It may be desired to impart retracted as well as advanced movement to the piston plug 20, as in the case of mixing other medicaments or the like with the contents of ampule I'I, by sucking the same into the ampule by way of needle I4. In this case, the plunger I2 is withdrawn from the barrel II to a position exposing the pin 28. The pin 28 is movedy to the lower end of slot 29 and then into portion 30. As a result, the threaded shank portion 26 on rod 25 projects outwardly of the lower, open end of sleeve 2 I. The plunger I2 is then pressed by means of thumb engaging piece 23 until the threaded shank portion 26 engages the piston plug 20. Upon rotating the plunger I2, the piston plug 20 will be pierced and gripped -by the threaded portion 26 on the rod 25. The penetration of portion 26 into plug 20 is limited by the enlarged portion 24 on sleeve 2I, so as to avoid contact with the contents of ampule Il, as shown in Fig. 2. With the piston plug 20 thus engaged, it may be moved in either direction by manipulation of the thumb engaging piece 23. The plug 20 is readily disengaged by suitably rotating the plunger I2 to withdraw the threaded portion 26. The frictional engagement of the plug 20 with the wall of ampule I'I permits operative engagement of the plug by the plunger I2. With the plug 20 engaged by the plunger, sticking of the plugwith respect to the ampule walls may be overcome by continued rotation of the plunger.

.-,The taper of theV conical shank portion 2'6 as 4 well as the sharp, self cutting thread formed thereon, permit ready penetration of the plug 20 as well as a firm grip thereon. Also, the plunger is not inadvertently pulled out of the plug upon upward movement of the plunger. It has been found that the withdrawal of the plunger from engagement with the plug is readily elfected by suitable rotation of the plunger. Upon withdrawing the threaded portion 25 of the rod 25 from the plug 26 and retraction of the rod 25 within sleeve 2I by means of pin 28, the plunger I2 is again ready for conventional use by abutting the portion 24 thereof against the plug 26.

It is understood that the ampule I'I may be retained within barrel I I against longitudinal movement by means well known in the art. Furthermore any ampule may be used with the syringe which includes a piston plug penetrable by. a self cutting thread.

It will be apparent that with the hypodermic syringe embodying the invention, conventional ampules provided with the usual imperforate pis'- ton plug may be used to provide either forward or retracted movement thereof. The construction of the plunger lends itself to quick conversion from one form of operation to another.

It will thus be seen that there is provided a hypodermic syringe in which the several objects of this invention are achieved, andwhich is 'well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, Within the scope of the following claims it is to be understood that all matter herein set forth or shown in the accompanying drawing, is to `be interpreted as illustrative and not in a limiting sense. v

` Having thus described my invention, I claim as new and desire to protect by Letters Patent:

l. A hypodermic syringe for use with an ampule having an imperforate piston plug, comprising a barrel, a plunger mounted Ain said barrel, said plunger comprising a slidable and rotatable sleeve open at one end, abutment means on said sleeve at the open end thereof adapted to contact said plug and advance the same upon slidable movement of said plunger in one direction, -a member slidably mounted in said sleeve and including a penetrating and gripping portion at one end thereof and means for retracting 'said member relative to said sleeve to bring the penetrating and gripping portion of said member to a position rearwardly of said abutment means, said` retracting means being further operative Vto move said member relative to said sleeve and to a position whereinthe penetrating and gripping portion of said member projects from the open end of said sleeve, whereby said plug may be positively engaged upon slidable and rotatable movement of said plunger.

2. A'hypodermic syringe comprising a barrel and a plunger mounted therein, said plunger comprising a slidable and rotatable sleeve open at one end and including vabutment means at said open end said sleeve further including a wall por,- tion formed with a longitudinal slot, a member slidably mounted in said sleeve, a pin on said member and disposed inA the slot of said Vsleeve for limiting the movement of said member relay tive to said sleeve in opposite directions, said member including a penetrating and gripping portion at one end thereof, said pin providing means for effecting relative movement between the sleeve and the member to selectively bring the penetrating portion of the member and the abutment means on the sleeve to an operative position.

3. A hypodermic syringe for use with an ampule including an imperforate piston plug, comprising a barrel and a plunger mounted therein, said plunger comprising' a pair of coaxial members arranged for relative axial and rotary movement, one of said members including abutment means at one end thereof for moving said plug in one direction, the otner of said members including means for positively engaging said plug for movement in opposite directions, interengaging means on said members for imparting movement to said second mentioned member upon movement oi said first mentioned member and means for moving said second mentioned member relative to said first mentioned member for engaging said plug.

ANTHONY DRABICKI.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,012,700 Payne Dec. 26, 1911 1,495,924 Quayle May 27, 1924 1,546,491 Kasmauskas July 21, 1925 1,712,069 Cressler May 7, 1929 1,718,602 Smith June 25, 1929 FOREIGN PATENTS Number Country Date 61,467 Germany Mar. 9, 1892 367,153 France Oct. 22, 1905 399,824 France July B, 1909 

